Preventing non-uniform shrinkage in open-die hot embossing of PMMA microstructures

The quality of a product made by hot embossing is affected by its cooling shrinkage. The special pressure-specific volume-temperature characteristics of polymer are such that the specific volume of polymer varies with pressure during cooling. Therefore, the shrinkage of polymer depends on the embossing pressure. This paper analyzes, both analytically and numerically, the pressure distributions on the surface of polymer during hot embossing process. The results indicate that a higher embossing pressure results in more uniform shrinkage in the elastically deformed state during cooling.